Forest ecosystems occupy the area of approx. 6 000 hectares, what constitutes 18,9% of the Park area. The main species forming the tree stand are common pine with 72,8% share in the wood stand as the predominating species, European white birch - 12,5%, black alder - 5,8 %, downy birch - 2,5%, Norway spruce - 1,3%, black pine - 1%. The other species such as European beach, pedunculate oak, European common ash do not exceed 1% share in all the tree stand of the Park. Pine tree-stands exist in almost all the settlements demonstrating a large differentiation of density, tree planting, quality classes and standards as well as the origin and age. In the Spit passage, one can meet the tree stands deriving from the natural re-newals and plantings, mainly in the dry or hardly humid settlements. They dominate in its eastern part.

These are the old tree stands in which over 100 year-old pine dominate. Current, approx. 70 year-old tree stand of alder and birch constitute a dominating element of the landscape around the Łebsko Lake. The western passage of the Spit between the Gardno lake and the sea has started to be drained and adopted for forestation since the mid of the XIX century. A high level of ground waters in the between-the-dunes depressions was a big problem in the progress of works. In the period of last 100 years, the area of forests in the Spit enlarged as a result of artificial planting as well as the development of natural pine tree stands. They constitute the first tree generation and their arrangement is irregular. The reason is the various manners of environmental management in this terrain in the former century. The area of the Park constitutes mainly poor settlements, which determine the existence of aci-dophilian forest accumulations. Therefore, there is a lack of typical dry-ground forests, marshy meadows or fertile beech woods, which exist here in poorer forms. The accumulations specific for the SNP are: relict beech wood and European beech-oak forest, marshy birch wood with European wax-myrtle, marshy coniferous forest with the heath and seaside crowberry forest. In Smołdzino Protection District the tree stands are of artificial origin often in formerly arable soils. In Kluki and Żarnowska Protection District, the tree stands cover the marshy and humid settlements. The young generation of the tree stand in the dry settlements is mainly pine, it is birch-tree and spruce in the humid and marshy settlements, however, a European beech and oak in the more fertile settlements. Such a large participation of pine in the tree stand causes the situation that in the Park predominantly coniferous tree stand exists, called coniferous forest. A peculiar kind of curiosity is the considerable proportion of extraneous species such as black pine and mountain pine which originate from the artificial planting performed in the years of 1900-1932 in order to maintain moving dunes fixation in the Łebsko Spit.